It's possible that you have a bad image file. Did you check the MD5 checksum of the iso image file? Also you need to burn the image to CD using the slowest speed. I have also had problems when I managed to get one of my paw prints on the CD and it couldn't read that part of the disk. To clean the paw prints off I use spray car wax/detailer spraying a little on the disk them cleaning it off with a soft paper towel rubbing cross ways on the disk not in circles.